Amphibious vehicles



Sept. 30, 1958 A. L. VAN RIET E-r AL MPHIBIOUSv VEHICLES 2 Sheets-Sheet 1 Filed March 10. 19.54

ATTORNEYS Sept 30, 1958 A. L. VAN RlET r-:T A1. 2,853,812

AMPHIBIOUS VEHICLES Filed March l0, 1954 2 Sheets-Sheet 2 ALPHONSE Lols VAN Rie-:1-

ATTORNEYS AMPHrroUs VEHICLES Alphonse Louis Van Riet and Robert Gustave Justin Coppens, Leopoldville, Belgian Congo Application March 10, 1954, serial No. 415,343

s claims. (c1. 37-144) The present invention relates to self propelled vehicles and more particularly to amphibious craft equipped with retractable tractor treads for use in shallow water marshes and swamp land.

This invention, although disclosed as applied to a boat, may be adapted for use on tanks, guns and other vehicles, civil or military which could obtain any advantage by selective operation on track treads and wheels.

Many shallow lwater streams, particularly in jungle and marsh areas, are made impassable even to shallow draft boats by shallow areas, weeds, or marshy terrain.

The present invention contemplates the use of retractable tractor treads mounted on either side of a conventional shallow draft boat. During navigation in normal passable waters the tractor treads are carried so the lower stretch of tracks is in a horizontal position above water level. Upon reaching an impassable stretch of stream the retractable treads on either side of the boat may be lowered by a unique system of linkage and power means attached thereto. By means of the simple rugged linkage the lower stretch of track is maintained in a horizontal position regardless of the shifting position of the track.

Another important feature of this invention involves the use of a bulldozing blade conveniently mounted on the forward portion of the tractor treads. With the tracks extended and using a bulldozing blade, in the manner to be described, this vehicle of the present invention may be utilized to perform such work, as scooping, leveling and filling under circumstances Where a conventional bulldozer cannot be used.

The Aadvantages of the present invention are best realized when applied to a shallow draft boat operating in jungle rivers, the course of which is alternately deep, shallow and weed choked. The deep sections of a stream or river require conventional marine propulsion yet the thrust of conventional marine propellers is insufcient to force a boatthrough many weed choked areas and can not force a boat through shallow areas and sand bars. When such obstacles present themselves to a boat equipped with the retractable tracks and bulldozing blade of the, present invention, the tracks may be lowered to the shallow bottom and the boat may proceed in the manner of a tractor. Should it become necessary toplow throughsuch obstacles as beforementioned, the bulldozing blade may be lowered into position ,and the boat becomes its own bulldozer to create a channel or path through the obstacles, maintaining excellent propelling characteristics because of the positive traction offered by the track treads.

A boat equipped-with retractable tracks and a bulldozerY blade, as herein disclosed, can be readily transported'under its own power to the middle of a stream for shallow dredging and removing sand bars, which cannot be accomplished by the conventional bulldozer.

landing craft can be well appreciated. It is known prior United States Patent O raising and lowering.

"ice

landing craft utilized chain tracks to gain access to the land, but the track treads were ixed to the craft structure, remained below water level during travel in the Water, and constituted considerable drag in opposition to passage through the water, resulting in slow labored water travel. As before mentioned, when a craft equipped with the retractable tracks of this invention is operated as a boat, the tracks are entirely above the water level and navigation and operation may be performed as in any normal boat.

This invention incorporates the track in a unit frame which may be readily mounted on a deck and the sides of a boat or land vehicle, the only Xed structure installation required being the main drive sprockets and power connections to the sprockets. For small craft the tracks may be made narrow and of light weight rubber or similar material whereas in heavier installations the tracks would be made of heavier, sturdier material. The invention further. contemplates the use of two or more pairs of tracks spaced at points along thev frame of larger boats and heavy land vehicles. Y

The drive for the track system utilizes a conventional tractor `differential connection to the main engine drive shaft whereby each sprocket is driven through the differential device at' the same speed unless the operator desires to brake either side of the differential for turning or maneuvering the craft during operation on the tractor treads.

With these and other considerations in View, it is' an important object of this invention to pro-vide a boat into and out of engagement with the ground.

Another object resides in novel supporting mechanism for mobile treads retractably mounted on aboat.

A further object resides in the provision of retractable treads on the sides of a shallow draft boat.

A still 1 further object resides in the provision of a novel arrangement in a propelled machine of retractable tractor treads in combination with a bulldozing blade.

An additional object resides in novel raising and lowering mechanism for mobile treads retractably mounted on a boat whereby the lower stretch of treads is maintained in a horizontal position during all positions between A still further object resides in novel guiding means utilizing and maintaining lateral sliding support between the tracks and the boat or vehicle frame in any position of the tracks.

Further objects and advantages of the invention will become apparent from the following description con-- sidered in conjunction with the accompanying drawings wherein the preferred embodiment is set forth in detail and from the appended claims. y f The preferred embodiment of the invention herein disclosed is illustrated in the following drawings in which: Figure l is aside elevation of the preferred form of the'invention showing the retractable treads incorporated on a 'shallow draft boat and wheren'the treads are also shownin phantom lines in lowered position;

Figure 2 isa partially sectioned plan view kof the arnphibious` craft shown in Figure l;

Figure 3 is an enlarged sectionalview of the track and frarnesupport structure taken on lines 3:-3v of Figure l; and

Figures 4 and 5 are side elevation views of modiiied f A retractable track structure, as applied to boats.

In the present embodiment of the invention the re-y together with raising and lowering block and tackle, at

As'rnayl be`r seen in the drawing a bulldozing blade is incorporated,

tions rather than being pushed through in the normal manner. A

` lGeneral description As the invention contemplates the vuse of retractable treads in amphibious craft, a shallow draft boat is illustrated in the drawings and incorporates a pair of retractable tractor tread assemblies 12, one on either side of the boat. Each track has associated therewith, lretracting mechanism, generally indicated at 14, suitably mounted in support structure 16. Support structures 16 are kmounted on the frame structure of the boat on the port and starboard sides at approximately deck level. Since the parts oflboth retractable tracks are similar, like reference numerals will be used to designate similar parts.

The tracks receive drive power from sprocket wheels 18 keyed or otherwise suitably fastened on shafts 20 suitably vjournalled in bearings 22 mounted concentrically within bosses 23 which are lixed tothe sides of the boat adjacent the aft end. The port and starboard shafts are connected by suitable gearing 24 to a clutch and differential mechanism indicated generally at 26. Mechanism 26 is connected through its clutch in conventional manner to the engine drive shaft and operates in the manner of conventional differential tractor drives, i. e., appropriate brake means are provided to individually brake either one of the track treads to maneuver the vehicle when operating on the treads. The engine is .connected through a reversing transmission mechanism to the propeller 30, the track drive mechanism 26 being connected to the engine drive between the transmission and propeller to enable the track treads to be driven in either direction. If desired, a ,simple clutch may beV incorporated in shaft 32 between the track differential mechanism 26 and propeller 30 to enable the operator -to disconnect the propeller if he wishes the propeller to remain idle while operating the tractor treads.

Retractable unit j .As best shown in Figure l, the retractable unit comprises a chain track 34 carrying treads 36 which may be rubber, steel or any other suitable material. Viewing the retracted position, Figure l, it will be seen that the ychain passes around and engages with sprocket wheel 18 and passes under supporting frame 38 and is guided thereon by small flanged idler rollers 40. The chain passes forward to an idler guide and support wheel 42 yand returns along the .upper side of frame member 38 guided by small flanged idler rollers 44 and a large guiding wheel 46.

Frame member 38 consists of two parallel vertical plates 48 and 50 and functions as the chain track guiding mechanism and the linkage between the retracting mechanism and the chain track. Parallel vertical plates 48 and 50 provide means rotatably mounting the forward idler guide and support wheel 42, the upper guide rollers 44, the large guide wheel 46 and an aft guiding and support wheel 52 which contacts the chain during extended operation. The lower edges of plates 48 and 50 are horizontal to the deck line or water line of the boat and, through suitable journals, provide mounting means Vfor the lower idler rollers 40. During track operation rollers 40 also help support the craft on the treads. The lower edges of frame 38 are maintained parallel to their original position during all positions of extending and retraction, by novel retracting mechanism land .linkage to be described hereinafter.

.In addition to support obtained from the retracting linkage, frame member 38 is also supported by novel interengaging structural connections to the boat frame.

' A split channel beam 54 4 is pivotally journalled on previously mentioned bossy 23 between the boat and the sprocket wheel 18. Beam 54 extends from boss 23 to forward idler guide wheel 42 and is suitably journalled on an elongated non-rotatable shaft 58. The split channel beam is in side-by-side relationship where it is journalled on boss 23 and remains in such side-by-side relationship for a short distance until clear of sprocket wheel 18 where the split channel beam separates to an inner member 60 and an outer member 62. extending in a. straight parallel relationship to pivotally engage shaft 58. An additional support plate 64 is 4welded on outer member 68 kand journalled on the end of shaft -20. It

' is thus seen that the split-channel beam forms an elonguide wheel 52 contacts the chain track 34 and together with idler rollers 40 and front idler guide wheel 42 will maintain the chain track in a horizontal position. As frame 38 moves down toward the extended position, beam 54 will pivot about boss 23 and front shaft 58 to the position seen in phantom view. Lateral support of beam 54 is provided by a dove tail fitting 66 pivotally mounted at .68 Iat the approximate midpoint of vinner beam member 60. Dove tail member 66 slides in a suitable arcuate dove tail track 70 which is riveted, welded or otherwise suitably affixed to the side frame structure of boat 10.

Further lateral stability and guiding means between support frame 38 and beam 54 is provided by suitably mounting dove Vtail tracks 72 on the open sides ofthe frame members 48 and 50 for sliding cooperation with dove tail vblocks 74 pivotally mounted on the inner and outer beam members 60 and 62. It will thus be seen that as beam 54 pivots about boss ,23, track 70 maintains proper vertical movement of the beam and through conjoint action of the laterally supported beam 54, track 72 and dove tail blocks 74 the supporting frame 38 is guide-d between inner and outer beam member 60 and 62 in a vertical path.

When frame 38 is lowered to an extended position, the upper large guide wheel 46 releases tension on the upper stretch of chain track 34. At the same time the large guide .and support wheel 52 contacts the lower stretch of chain 34 and together with rollers 40 takes up any slack allowed by repositioning of frame member 38. Y v

Retraczing mechanism units The track retracting mechanism 14 comprises packaged power units and connecting linkage arranged within a vertical planar frame structure 16 including base plates 80, vertical side plates 82 and parallel horizontal beams 84. By this vertical arrangement of the retracting mechanism disposed on the sides of .the deck structure of boat 10 the major central surface of the deck remains clear of retracting mechanism enabling lthat portion of the deck to be utilized for other purposes, such as carrying cargo or, as disclosed in the drawings, for mounting structure to raise and lower a bulldozing blade to be described hereinafter.

Referring now to Figure 2 it will be noted that `the retracting mechanism is shown on the port side as atop plan view while the starboard retracting mechanism `is cut away to show the connections between the power units 86 andthe retracting linkage. The power units may be hydraulic servo motors as indicated, powered yscrew jacks,

worm and gear arrangement or any other suitable power arrangement. f

APower units 86 are disclosed as hydraulic servo motors and include cylinders 88 having diametral opposed stub shafts 90 integrally fixed thereto and journalled in pillow block bearings 92 which are fastened to support plates on the vertical side plates 82 by any suitable means. The servo motors are thereby pivotally mounted to swing about an axis transverse to the vertcal side plates 82 for a purpose that will become apparent as the description proceeds. Each retracting mechanism includes two power units 86 positioned adjacent and between the fore and aft ends of vertical side plates 82 with their reciprocable connecting rods 96 arranged in opposed relation. The free ends of connecting rods 96 are journalled on a connecting pin 98 carried in the end of a rocking lever 100. Lever 100 is pivotally journalled at a point intermediate its length by shaft 102 in bearings 104 suitably mounted at the approximate mid points of horizontal beams 84. On the rocking lever 100 at the opposite `side of the pivot from connecting pin 89 are two lever arms 106 and 10.8.

Two bell crank levers 110 and 112 are similarly pivotally journalled at the aft and `forward ends, respectively,.of horizontal beams 84. Bell crank lever 110 includes a short arm 114 and a long arm 116 while bell crank member 112 has a short arm 118 and a long arm 120. Pivoted links 122 and 124 connect respectively between lever arm 106 and short bell crank arm 114 and between lever arm 108 and short bell crank arm 118. The long arm 116 of bell crank 110 is pivotally connected to an olf-set fork link 126 that straddles chain 34 and is pivoted by flathead stud members 128 to the side plates of frame member 38. For convenience in assembly, fork lever 126 may be made in two parts. The long arm 120 of bell crank 112 pivotally mounts one end of a link 130 whose other end 132 is xed by welding, keys and keyways or other suitable means to shaft 58. As seen in Figure 2 shaft 58 passes from one chain track across the front of the boat to the other chain track. `As before stated, shaft 58 passes through beam 54'and supporting frame 38 and journals the front idler guide wheel V42 between supporting frame plates 48 and 50. l

As power units 86 move the swinging lever 100, bell cranks 110 and 112 will be pivoted in opposite directions to either raise or lower the supporting frame 38 by their connecting links 126 and 130. Note that the kinematics of the various linkages are so constructed and arranged that the vertical movement of pivot studs 128 and shaft 58 are equal. Equal travel of these two frame support points assures the bottom edge of support frame 38 remaining in a horizontal position or a position parallel to its original position from retracted to extended position.

Power is provided for hydraulic servo motors 86 by an engine drivenhydraulic pump 134 and hydraulic reservoir 136. No hydraulic control system has been shown, however, any conventional control systemincluding a reversible control valve and a high pressure relief valve between the pump line and the return line may be utilized.

Bulldozng blade unit The bulldozing blade 140 is mounted at three points to the retractable track structure. Adjacent each end of blade 140 fork fittings 142 are suitably fastened, preferably by welding. The free ends of the forks are laterally arranged and bored to receive a pin 144. An expansible bar link 146 is pivotally connected to fork fitting 142 by pin 144 to pivot about an axis substantially vertical and parallel to the dozer blade face. The opposite end of bar link 146 is pivoted about a pin 148 to yoke member 150. Pivot pin 148 is parallel to pivot pin 144. Yoke member 150 embraces the inside of inner beam member 60 and the outside of outer beam member 62 and is suitably journalled on shaft 58.

The expansible bar link 146 comprises a channel member 152 and a bar member 154 of a proper size to tit l boat will thusl be enabled to travel any navigable river or v within vthechannel member 152. As will be noted in Figure l the position of bar member 154 relative to channel member 152 may be varied by removing pins 156 and placing them `in appropriate holes 158 formed in member 152.

At the mid-point of they bulldozing blade 140 a third fork fitting 160 similarto fork fittings 142 is suitably fastened, as by welding. Fork fitting 160 is pivotally connected by pin 162 to the apex of an A-frame 164 whose leg members 166 are journalledon shaft 58 at axially fixed positions on shaft 58 by suitable means suchas the fixed collars 168. Collars 168 may be fixed to shaft 58 by set screws, through pins or welding.

By means of the three pivot connections, 142, 160 and 142, the bulldozing blade may be positioned for a straight pushing action or, by removing the pins 156 from the expansible bar links 146, shortening one of the expansible bar links and lengthening the other, the blade 140 may be Operation During navigable water operation of the amphibious boat the tracks and associated mechanism are retained in a retracted position and the bulldozing blade is held in an elevated position a sufficient distance above the water level to prevent inadvertent engagement of the blade with the water. As lhereinbefore mentioned the tracks when in retracted position, are maintained out of and above the level of the water preventing unnecessary drag against the passage of the boat through the water. The

stream in a manner identical to any shallow draft boat. ShouldV the navigable stream or river turn into shallow weed infested areas the boat operator would merely disengage the propeller, operate the hydraulic valve to direct hydraulic pressure to the rear end of the forward hydraulic servo motors 86. This action would relieve hydraulic pressure in the rear hydraulic servo motors and enable connecting rods 96 to move in the aft direction thus rocking swinging lever in a clockwise direction. Through connecting linkage bell crank is rotated in a counterclockwise direction and bell crank 112 is rotated in a clockwise direction to simultaneously lower both ends of support frame 38. The front idler support `wheel 42, the rear idler support wheel 52 and the small idler guide rollers 40 carry the chain track in a horizontal position toward the extended track position. on the bottom of the stream or river and through the differential gearing 26 and drive sprockets 18 the craft will be able to propel itself through the shallow area. Should it become necessary to clear any obstructions out of the way the block and tackle 172 can be lowered to bring the bulldozing blade into action. The craft is thus enabled to perform as a bulldozer and clear its own path.

The amphibious craft is not necessarily restricted to shallow water navigation but may be utilized as a shallow channel dredge or to construct ditches in marshy lands, help build levies and move sand banks along streams and r1vers.

The vertically retractable, side carried chain tracks, when used in conjunction with heavier craft or vehicles can be arranged as disclosed in Figures 4 and 5 wherein the front idler wheels 42 and 42" are journalled on shafts fixed .to the craft structure rather than on the vertically shifting frame as used with small craft and disclosed in Figures l and 2.

The modification disclosed in Figure 4 has the sprocket The track will resty drive wheel 18 and idler wheel 42 journalled in bearings xed to the crafty structure. Frame member .38 is .constructed .in a manner similar to frame member 13S-except it shifts in a straight vertical path on straight dove-tail tracks 180 and includes four large idler guide wheels 46 and 52. The small anged idler guide rollers 40 and 44' are similar to idler rollers 40 and 44. The retracting and extending units for the modiiied retractable tracks would be identical to the vertical planar retracting units 14 in Figures 1 and 2 except the linkages would be adjusted to enable straight vertical travel of frame 38.

The modification of Figure contemplates eccentric wheels 182, journalled on eccentrically positioned shafts 184 which are fixed to the'craft structure. The chain track is mounted on sprocket 18" and idler wheel 42" fixed on craft structure as in Figure 4. In this adaptation a plurality of idler rollers 186 are suitably journalled around the periphery of eccentric wheels 182y andy guide and support the chain tracks. To extend or lower the chain tracks all eccentric wheels are rotated in unison by interconnected gearing on shafts 184 to position the tracks in a downward position. If desired for additional rigidity, arcuate dove tail tracks 188 are provided for cooperation with suitable guide blocks on the eccentric wheels 182.

be utilized instead of interconnected gearing. vAlthough beams pivoted to said .boat .on theV axis of said sprockets and extending beyond the front end of said boat, a shaft` connecting .said beams ahead of said boat, a pair of planar frame members pivoted to said beams on Athe axisof said shaftlconnecting said beams, a pair of idler wheels carried by said frame member and pivoted thereto on the axis of said shaft, said idler wheels being in continuous engagement with ,said tracks, and power units .positioned along the side edges Vof said boat and connected to said planar frame members to raise and lower said frames to extend and retract said mobile tracks.

Figure 5 discloses only three eccentric wheels, any ,num-

with. that obtainable by the structure illustrated in `Fri-gures 1 and 4.

As is apparent the side mounted,retractable -chain' tread is not restricted to boats but can be utilized `onlaudcraft as well and is as applicable to both civilian an military use. Y

This invention may be embodied in other speciic forms without departing from the spirit or essential characteristics thereof. The present embodiments shown are therefore to be considered in all respects as illustrative and not restrictive, the scope of the -invention being indicated by the appended claims rather than by the Nforegoing description, and all changes which come within the meaning and a range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States :Letters Patent is:

1. An amphibious craft comprising boat structure having a source ofy power, means disengageably connected to said source of power for propelling the'boat-in the water, a pair of retractable mobile tracks, one Vmounted alongside each side of said boat and interconnected therewith for movement vertically between a position above the waterline to a position in which the lower portion `of the track extends below the bottom of the boat, sprocket wheelsjournaled in vthe side of the boat above the waterline and continuously engaging said tracks, a pairfof 2. An amphibious craft as set out in claim 1 including a tpair of spaced arms pivotally 4attached to said shaft and carrying `a bulldozer blade, and power means for raising and lowering said bulldozer blade. Y

3. An amphibious craft as set out in lclaim 1 including a -iirstvv pair'of track members mounted on said planar frame members, ytrack interengaging members of said beams engaging said track membersifor lsliding movement therebetween, a secondpair of track members on said boat, and .a second pair of `track interengaging members engaging said second pair of track members for `sliding movement therebetween.

4. An amphibious craft as set out in kclaim 1 wherein said power units include a pair of forward bell crank levers connected to `said shaft, a pair of rear bell crank levers connected lto said frames, and means for rotating all bell crank levers simultaneously. l t

y5. An amphibious craft'as setrout :in claim 4 Where said 'Last `named means includes a pair of hydraulic power unitsone of said units being connected by levers to .one of said forward bell crank leversand to one of said rear bell crank levers, the other of said units being `connected `by rlevers to the other forward bell crank lever and to the other rear bell crank lever;

VReferences Cited in the tile of this patent UNITED STATES PATENTS Des. 143,365 Sutphen Dec. 25, 1945 990,487 Lilleberg Apr. 25, 1911 1,233,840 Burgess July 17, 1917 1,534,514 Gebr-ung Apr. 21, 1925 `1,686,517 Cook Oct. 9, 1928 1,700,384 Stachnyk Jan. 29', 1929 1,890,228 e Miller Dec.. 6,1932 2,105,042 -Kegresse Jan. l1, 1938 2,351,799 Y Austin June 20, 1944 2,374,240 Shankman Apr. 24, 1945 2,495,057 Dillingham Jan. 17, 1950 2,551,967 Pouliot May 8, 1951 FOREIGN PATENTS 480,652, Germany Aug. 7, 1929 k647,798 l Germany July 13, 1937 V265,670 Great Britain Feb. 7, 1927 288,695 Great Britain Apr. 1.0, 1928 

